Arc-light electrode.



No. 859,890. PATENTED JULY 9, 1907.

R. H. READ.

A110 LIGHT ELECTRODE. APPLICATION FILED 0013.26. 1902.

Witnesses Inventor.

% Robert H. Read.

7 v by when expoxeed to the atmosphere.

; UNITED s'r Es P ENT OFFICE.

nonnnr nflti Al), OF SCIIENEOTADY, NEW. YORK, ASS IGNOR 'lO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ARC-LIGHT ELECTRODE.

No.8b9,890.- I

Specification of Letters Patent.

Patented July 9, 1907.

Original application filed May 18, 1901, Serial No. 60,813. Divided and this application filed October 26, 1902. Serial No. 128,786-

To all whom it may concern:

Be it known that l, Ronnu'r H. READ, a citizen of the United States, residing at Schenectady, county of Sclnrnectady, State of New York, have invented certain new and useful Improvements in Arc-Light Electrodes, 91' which the following is a specification.

This invention relates to are lighting, the object being to improve the quality of the light and permit the maintenance of a longer are with currents of moderate potential and amperage. I have discovered that conducting electrodes for are lamps formed of the conducting carbids or containing a considerable portion of the same, permit a much longer are to be drawn with the same potential and current than corresponding electrodes of carbon. The action of the arc is also much smoother than a carbon are, being remarkably quiet, the tendency of the tips at the are terminals -being to fuse slightly before being vaporized, thus conducing toward a quiet action free from hissing or decrcpitation and much more stable than a carbon arc. The color of the light varies'with the base of the carbid; for example, an arc containing carbid of calcium has a rich golden color of intense luminosity, Whereas one formedof or containing aluminium carbid has a much whiter appearance, the spectrum varying with the nature of the carbid.

I prefer to employ carbids which are unaffected by moisture and therefore do not deteriorate in service For example, carbid of calcium s unsatisfactory for practical service unless mixed with conducting bond or compound which protects each particle of the carbid from access of moisture; whereas aluminium carbid which is unaffected by moisture at ordinary temperatures does not require such protection.

The present application is directed to the form in which a decomposable carbid is employed, claims for non-decomposable carbids generally, and for aluminium carbid being made in my original application Serial Number 60,813, filed May 18, 1901, of which the present application is a'division; and claims for certain other forms of carbid, as for example, titanium, being cov-v ered in my divisional application .Serial Number 126,669, filed October 10, 1902.

Where carbids of lithium, calcium, strontium, barium, lanthanum, yttrium, thorium and manganese, or generally any carbid which is attackableby cold water is employed, the electrode should be formed of a mixture of ground carbid mixed with coal tar or similar carbonaceous binder baked and raised to incandescence out of contact with air, and then parafifined or similarly protected on the outside from moisture; or such compounds may be employed as a'core for a hollow carbon. If cored electrodes are employed care should be observed to protect the core from access of moisture by coating the carbon with paraflin or metal or other moisture-proof material, as the allinity of such carbids as are decomposed by cold water is so strong that moisture is absorbed throughthe pores of the carbon, and soon splits the electrode along its axis. Much more satisfactory results may however be secured by the carbids ofaluminium, chromium, zirconium, molybdenum, titanium, Wolfram, which are not attacked by water at ordinary temperatures, or at least very slightly so. I find that carbid of aluminium gives excellent results either when employed pure or when mixed with a carbonizable binder, molded and baked;

and by reason of its cheapness and 'ease of manufacture is most feasible for ordinary uses. for a core for a cored carbon.

In preparing the electrodes the material as produced in the electric furnace is finely pulverized and molded in sticks of the desired size by mixing with it about 5 of a carbonizable binder such as cane sugar or wheat flour, moistened with a small quantity of coal tar or even cold water. After drying and baking at a bright red heat, its structure may be rendered more compact'and dense by filling the pores with carbon by any approved process, such for example, as saturating with sugar and again firing, or by raising to a red heat in a hydrocarbon vapor. When burning in an automatic lamp it is desirable to provide for a slight lateral or scraping motion in drawing the arc to rub away the deposit of oxid liable to form at the tips of the electrodes, which is a good non-conductor of electricity. The lateral movement rubs off the thin film of oxid It may also be used and gives a conductive connection which permits the arc to be struck, after which it is maintained with more stability than an are between simple carbon electrodes.

ciently good conductor to act as a carrier of current.

When used with an inclosing globe, the lamp in which the electrodes are used should be provided with a wiper for periodically removing the deposit from the walls of the globe or this could be effected by providing a draft through the inclosing globe; the latter expedient however greatly reduces the'life of the electrodes and increases the expense of maintenance. I

fi nd that with electrodes of carbid of calcium or carbid 1 of aluminium, for example, a good arc from light.

In the accompanying drawings, Figures 1 and 3 illustrate elevations of are light pencils of different sizes formed according to my invention; Fig. 2 shows a cored electrode.

The electrodes may consist of sawed sticks of a crystalline carbid or may be composed of a carbonized compound ofthe carbid and the carbonaceous material, asabove set forth; 1 representing an electrode suitable for a 5-ampere lamp, and 2 one suitable for a l-ampere lamp.

3 represents a hollow carbon pencil, and 4 a core of conducting carbid compound, as above described.

What I claim as new and desire to secure by Letteis Patent of the United States is,

1. As a new article of manufacture, an arc lamp electrode of cnrbld having a covering envelop impervious to water to protect the electrode against the decomposing action of the moisture of the air.

2. As a new article of manufacture, an arc lamp eiectrode of carbid having a solid metal envelop protecting the carbid from moisture. i

3. An are light carbid electrode, containing carbid do composable by water and conducting substances lncorp0- rated in the body of the carbid, and a superficial coating of a body impervious to water.

4. An are light carbid electrode, containing carbid of calcium a conducting substance. incorporated in the body of the carbid, and a superficial coating of a body imper-' vious to water.

5. An are light carbid electrode, containing calcium carbid and carbon mixed therewith, and a superficial coating of a body impervious to water.

6. An are light carbid electrode containing carbid of vious to water-to protect the electrode against the decomposing action of the moisture of the air.

8. As a new article of manufacture, an arc lamp electrode containing'n carbld decomposable by cold water having a covering envelop impervious to water to protect the electrode against the decomposing action of the moisture of the air. q

OfAs a new article ofmanufacture, an arc lump electrode containing curhld having a solid metal envelop protecting the cal-bid from moisture, substantially us described.

10. As a new article of nmnufucture, an arc lump electrode containing a curbid decomposable by cold water, having a, protective envelop of metal.

11. An are light electrode containing a conducting curbld and a conducting binder intimately associalcd throughout the mass.

12. An are light electrode containing a conducting curbid and a carbonized binder intimately associated throughout: the mass.

13. An arc lamp electrode comprising a carbon pencil cored with a conducting curbid intimately associated with a conducting binder throughout the mass of lvllc cole.

l-lfAn are light electrode comprising a carbon pencil cored with a cnrbid decomposable by cold water, intimately associi'ited with a carbonized binder throughout its mass.

15. An are light electrode comprising a carbon pencil cored with carbid of calcium intimately associated with a conducting binder throughout its mass.

16. An are light electrode formed of granular conducting carbid united by a" conducting binder.

17. An are light electrode formed of molded material containing carbon and a conduetingparbid.

18. An are light electrode containing granular or finely divided conducting carbid having its pores filled with carbon.

19. An are light electrode containing a conducting carbid having its particles bound'together by a small percentage of carbon. I I

20. An electrode, comprising a carbid and a carbon binder, as set forth.

.21. An electrode, comprising a carbid and a coked binder, as set forth.

22. An electrode, comprisingcalcium carbid and a carbon binder, as set forth.

23. An electrode, comprising calcium carbid and a cokedbindr, as set forth.

In witness whereof I have hereunto set my hand this 24tlrday of October, 1902.

ROBERT H. READ:

, Witnesses:

ALEX. F. MAcnoNAnD, GENEVIEVE HAYNER. 

